STAR-CCM+ High Performance Computing Simulations of Oil Shale Retorting System Using Co-Simulation

At the Institute for Clean and Secure Energy at the University of Utah, we work closely with industrial partners to assist in commercial utilization of energy from oil shale and oil sand resources. For the past two years, we have been working with American Shale Oil Corp (AMSO) to simulate their pilot process located in the Piceance Basin, Colorado, the richest known oil shale location in the world.

Our initial simulations of the system included only the conductive effects associated with heating the formation, which over-predicted the temperature distribution throughout the formation. In our latest high performance computing (HPC) simulations using STAR-CCM+, we capture the entire pilot test system, including the heater surrounded by oil, which in turns heats the shale formation. To resemble the actual field pilot test, we capture both the convective as well as conductive time scales inside our simulations. The small convective time scales are on the order of seconds and occur in the oil surrounding the heater. The large conductive time scales are on the order of days and occur in the shale formation.

To be able to simulate months of heating of the formation, we use the co-simulation feature in STAR-CCM+. This feature allows us to subdivide our computational resources and thus resolve the convective currents in oil surrounding the heater, and to still capture the solid heat transfer occurring inside hundreds of meters of shale formation on a centimeter scale. By using STAR-CCM+ to simulate the entire pilot test system at once, we are able to closely match the thermal temperature profile throughout the formation as measured in the field. Therefore, now we can use this simulation process to optimize the heat transfer throughout the formation to maximize the oil yield.